This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. This protocol is directed to providing the clinical data and associated biological samples which will enable a broad based effort to identify genetic and immunological factors that cause autism and related neurodevelopmental disorders. Specific aim 1 will address the hypothesis that de novo genetic changes occur in autistic subjects, and that these changes can be causative when present in a permissive genetic background. Specific aim 2 will address the hypothesis that antibodies circulating in the mothers of autistic individuals can play a role in the development of autism as a result of exposure of the fetus to such antibodies during intrauterine development.